The Greenfield system uses large forward and reverse clutches - it does not use a slipping belt as a clutch as smaller tractors often do. The only vulnerability of the belt system I know of, is that sometimes the automatic tensioner in the wheel drive belt doesn't quite take up a notch, and the belt slips on steep slopes until someone applies a lever to the spring-loaded pulley and pulls it backward to engage the next notch. I would expect the owner to do that himself on the rare occasions it is necessary, it is only a two minute job and hardly justifies hauling the tractor to a service center.
I have to wonder whether your dealer actually knew what a Greenfield is and how its drive system works. There are popular machines that use slipping-belt clutches, and in constant heavy-duty service they could consume belts and belt pulleys fairly quickly, but the Greenfield just doesn't work that way.
